One of the more positive outcomes of Ed Miliband's election as Labour leader is that his social liberalism is beginning to manifest itself in party policy. He made it very clear during the campaign that he thought the previous government had gone too far with its assault on civil liberties. Now Ed Balls, amongst the most authoritarian and statist members of the shadow cabinet, is admitting the same: he has indicated that Labour may back moves to reduce the period of detention without trial from 28 to 14 days. He has also dropped any calls for the use of ID cards, although the position on the use of CCTV will remain the same.

So what? Well, the mark of a successful government is not one that enacts bold reforms, but one that makes those reforms politically irreversible. The easiest way to do this is to achieve cross-party consensus on reform, or else cause a tectonic shift in political debate, making certain realms unelectable. New Labour emerged as a response to Thatcher and Major – it dropped the more economically illiberal elements of Labour policy in order to become electable. Likewise, the Conservatives have had to become increasingly socially and culturally liberal in response to the Blair years.

Although the consensus may be shifting in favour of civil liberties, we must ensure that it shifts far enough. As Alex Deane of Big Brother Watch rightly points out, the debate must now move towards whether we want to go lower than 14 days. Shifting the political tectonic plates takes incremental change, but the shift must not end with what an ostensibly liberal Labour party will accept – the defence of civil liberties has the potential to become the coalition government's most enduring legacy if it takes truly bold steps to secure them.